Regenerative Trace Contaminant Control: New Test Method for Effects on Solid Amine 921349
Tests using the Thermogravimetric Analysis (TGA) techniques showed this approach to be a relatively simple and rapid method for assessing the affinity of trace contaminants for a solid amine, CO2 sorbent. Regenerative CO2 sorbents are applicable to many space systems air revitalization applications for removal of CO2. Sorbents may be chemically non-specific as regards reversible adsorption-desorption, chemicals other than CO2 can be regeneratively removed from spacecraft air. These other chemicals, present in trace amounts, may also interfere with the primary CO2 removal function. TGA test procedures were developed to determine adsorption-desorption behavior of trace contaminants on a regenerative solid amine sorbent: Hamilton Standard, material - C (HS-C). Seven trace contaminants were tested; the TGA test procedures:
Evaluated the TGA method for studying sorbent materials in air revitalization systems
Determined the adsorption/desorption characteristics of the HS-C to CO2
Detailed the adsorption/desorption effects of trace contaminants on CO2 removal
The tests showed trace contaminants to be in one of three classes:
Regeneratively adsorbed and desorbed
Inert, no effect
Poison - interferes with CO2 removal.
Trace contaminants which poison the sorbent can then be identified and design provisions in air revitalization systems made. Acetone, in dry air at 1% concentrations, bonds irreversibly to the HS-C material. With the exception of acetone, the other six trace contaminants effected a slight reduction in the CO2 adsorption/desorption function. Methanol, Freon 21, and Freon 13B1 were adsorbed and fully desorbed, indicating the possibility of regenerative removal of these contaminants.